Drive Device and Drive Method for Vacuum Fluorescent Display

1. A driving device for a vacuum fluorescent display which includes an anode unit constituted by a plurality of fluorescent substance-coated anodes arranged in a matrix pattern, and a cathode filament that emits electrons toward the anode unit, the device comprising: a first magnetic field generating means configured to generate a first magnetic field vertical to a direction in which the anode unit and the cathode filament face each other, and of which polarity is switchable periodically; and a second magnetic field generating means configured to generate a second magnetic field vertical to a direction in which the anode unit and the cathode filament face each other and vertically crossing the first magnetic field, and of which polarity is switchable periodically.

2. The driving device of the vacuum fluorescent display according to claim 1 , wherein a first and a second alternating currents different in at least any one of amplitude value, frequency, and phase are respectively supplied to the first and the second magnetic field generating means.

3. A driving method for a vacuum fluorescent display which includes an anode unit constituted by a plurality of fluorescent substance-coated anodes arranged in a matrix pattern, and a cathode filament that emits electrons toward the anode unit, the method comprising generating a first magnetic field vertical to a direction in which the anode unit and the cathode filament face each other and a second magnetic field vertical to a direction in which the anode unit and the cathode filament face each other and vertically crossing the first magnetic field, with the directions switched periodically.

4. The driving method for the vacuum fluorescent display according to claim 3 , wherein the first and the second magnetic fields are generated respectively by the first and the second alternating currents different in at least any one of amplitude value, frequency, and phase.